CONDUCTIVITY OF WEAKLY INSULATING AMORPHOUS NICKEL-SILICON FILMS BELOW THE METAL-INSULATOR-TRANSITION

The electronic conductivity has been measured in homogeneous, weakly i nsulating, amorphous nickel-silicon films located just below the metal -insulator transition (MIT). The conductivity follows a simple CTz pow er law dependence with z approximate to 1/2 over a large temperature i nterval The CTz behavior can be explained using the scaling theory sug gested by Di Castro. A Mott variable-range hopping law cannot be fitte d successfully through the zero field data.